Solution of alkaline silicates and process of preparing the same.



COATING R PlASTIC.

1m i) STATES- PATENT onnron.

JAMES G. 'VAIL, OF CHESTER, AND JOHN D. CARTER, OF LANSDOWNE, PENNSYLVANIA.

SOLUTION 0F ALKALINE SILICATES AND PROCESS OF PREPARING THE SAME.

No Drawing.

To all whom it may concern:

Be it known that we, JAMES G. VAIL and JOHN D. CARTER, citizens of the United States, and residents of the city of Chester, county of Delaware, and State of Pennsylvania, and of Lansdowne, county of Delaware, and State of Pennsylvania, respectively, (whose post-oflice addresses are: in care of the Philadelphia Quartz Company, Chester, Pennsylvania,) have invented certain new and useful Solutions of Alkaline Silicates and Processes of Preparing the Same, of which the following is a specification.

While it has been recognized that solutions of alkaline silicates, such as sodium silicate, are well adapted for use as a medium or vehicle for fire-resisting, and other paints or varnishes, was for other purposes, it has hitherto been impossible to produce such a solution, which, when dry, would alone form a coating sufiiciently insoluble for commercial purposes. It has therefore been necessary to combine the silicate solution with various active substances of such nature that the resulting reaction would form a product, which, when dry, would form an insoluble, or practically insoluble, coating.

Among the principal objects of our 1nvention are to produce a solution of an alkaline silicate, which, when .dry, shall be ractically insoluble; to produce such a soution, which may be used by itself as a transparent varnish or coating, or which may be used as a medium or vehicle for mixture with other substances of any desired nature to form a paint or varnish, and which, when so used, either alone or in combination with other substances, shall produce a coating which will be practically unafi'ected by atmospheric or climatic conditions; and to produce such a solution which may be evaporated to a viscous condition alone, or made into a pasty condition in combination with other substances, and thereafter diluted by the addition of water or othei-liquids to any desired extent.

Further objects of our invention are to produce a olution of an alkaline silicate which mae kept indefinitely in closed receptacles, lther alone, or in combination with other substances. but which, when dried by exposure to the air or otherwise, shall form a practically insoluble, fire and weather resisting product which may be em-' Specification of Letters Patent.

paints or varnishes, various i Patented Feb. 23, 1915.

Application filed October 22, 1918. Serial No. 796,559.

Our invention further includes all of the various other novel features and objects hereinafter more definitely specified.

We have found that if silicic acid before silicate the resu 1nro1 lution of ala me reaction. which when my forms a substantially insoluble poun w] on 1e a 1 10D 0 ot ier ingreien s. In the practice of our invention, we have found that good results may be obtained by the dilution of a given quantity of a solution of an alkaline silicate, such as so dium s1 icate, w] su an 1a ly ten am is weight of water, the dilute solution thus obtained being acidified wit a suit.

quan 1 yo substantially equa in amount to t e u solution, may be added. The resulting it has assumed its elatinou 's'cliaracter 5e 75 A suitably combined with an excess of a solua liquid is an alkaline solution of the silicat which has the property of forming an msoluble, or practically insoluble, product af-. ter being dried by evaporation or otherwise. It is believed that many of the valu-' able properties of the liquid so produced may be attributed to the actionof the silicic acid, liherated i n the dilute solution, 1n 1e presence of the excess centrated alkaline solii-tion, and it may therefore be possible to produce a substance having similar properties by otherwise bringing silicic acid into contact with an excess of a s'uitably concentrated solution of an alkaline silicate, as for instance, by adding a dilute-solution of a suitable acid to an excess of a suitably concentrated alkaline silicate. For the purpose of producing other substances may be mixe W1 .his

ents or.

it maybe therefore, may be made of numerous inert i cuts the product presenting a satis- Ea ctory medium or vehicle for the use of such substances, being adapted, as it is, to form, after drying, a difiicultly soluble coating independent of the action of substances which may be combined with it.

If desired, the product as hereinbefore described, may be ev orate d gp othegjse reduced l u t on, or may be ma'd ihto a pasty conditio by combination with suitable substances, and as thus prepared, may readily and economically be transported and kept until it be desired to make use thereof, at which time, the mass may be diluted to a proper consistency by e addition of water or other liquid. It has been found that if the product.

'after being spread upon a given surface, and allowed to dry, be immersed or otherwise washed in water for a sufiicient period, its strongly alkaline reaction will gradually disappear, until at last it cannot be detected even by careful tests, the product appearing to have become absolutely neutral. This peculiarity in no way, however, impairs or afiects its valuable commercial features, or detracts from its durability or fire-resisting properties.

We do not desire to confine ourselves to the production of a solution of an alkaline silicate having the properties of our discovery solely by means of the process hereinbefore described, although we have found that process to be well adapted for the commercial production of the article. Furthermore, when such process is employed, it will be evident that various changes may be made in the proportions of the ingredients or in the degrees of concentration thereof, or in the condition under which it may be carried out, in order to adapt the process to the most economical and satisfactory preparation of the product for commercial use, and that the resultin product as heretofore set forth may be mixed with various substances to form paints or varnishes or the like, or used for other purposes such as cement, as may be desired, and that other changes and modifications may be made without departing from the spirit and scope of our invention as defined in the appended claims.

Having thus described our invention, we

claim and desire to protect by Letters Patent of the United States:

1. A solution of an alkaline silicate forming a substantially insoluble product when dry.

2. A solution of sodium silicate forming when dry a difiicultly soluble'product.

3. An alkaline solution composed of a neutralized solution of a silicate to which has been added a concentrated alkaline solution of a silicate.

4. An alkaline solution composed of a neutralized solution of sodium silicate to which has been added a predetermined quantity of a concentrated alkaline solution of sodium silicate.

5. An alkaline solution having the property of forming a substantially insoluble product when dry, prepared by the formation of silicic acid in the presence of an excess of an alkaline silicate.

6. An alkaline solution prepared by the combination of an acid capable of decomposing sodium silicate and a solution of an alkaline silicate of a dilution sufiicient to prevent the instantaneous preci itation of the liberated silicic acid, said so ution having the property of forming a substantially insoluble product when dry.

7. An alkaline solution composed of a dilute solution of sodium silicate which has been neutralized with an acid, and a concentrated solution of sodium silicate.

8. An alkaline solution composed of a dilute solution of sodium silicate which has been slightly acidified, and an excess of a concentrated solution of sodium silicate.

9. An alkaline solution capable when dry of formin a difiicultly soluble product, prepared by t e mixture of a dilute neutralized solution of sodium silicate with a concentrated solution of sodium silicate.

10. The process of preparing a solution of an alkaline silicate, which consists in neutralizing a dilute solution of the silicate and then adding thereto a concentrated solution of the silicate.

11. The process of preparing a solution of an alkaline silicate which will form a practically insoluble product when dry, which consists in first neutralizing a dilute solution of the silicate with an acid and adding thereto a concentrated solution of the silicate.

12. The process of preparing a solution of an alkaline silicate which will form a substantially insoluble product when dry, which consists in first slightly acidifying a dilute solution of the silicate with a suitable acid, and then adding thereto a concentrated solution of the silicate.

13. The process of preparing a solution of sodium silicate which when (1 will form a diflicultly soluble product, which consists in first neutralizing a dilute solution of so- 1 0 106. COMPOSITIONS, Lxumm COATING OR PLASTIC.

dium silicate with a suitable acid and then In witness whereof, we, James G. VAIL 10 adding thereto a concentrated solution of and JOHN D. CARTER, have hereunto set our sodium silicate. hands this 20th day of tenth month, A. D.

14. An insoluble coating for a surface 1913.

5 comprising a solution of a silicate in com- JAMES G. VAIL.

bination with a pigment, said solution being JNO. D. CARTER. operative when dry to form a substantially Witnesses: insoluble coating without the assistance of HENRY W. JONES, the pigment. Bnssm Tamra.

copies of this patent may be obtained for five cents each, by addressing the "commissioner of Patents, Washington, D. 0. 

